lint.sh: fix path to get-upstream-commit.sh
lint.sh: fix path to get-upstream-commit.sh

8a758f7c292764ffcb737c61c643cc34517e836e changed this script to avoid use of
'readlink' on OSX, but broke the path to find get-upstream-commit.sh.

Change-Id: I7e3a0348ea5c6225765c3d4f66c9e4ad09d619d8
Reviewed-on: http://gerrit.cloudera.org:8080/1328
Reviewed-by: Mike Percy <e07a1fd797b473a9c849e618aa2ce06d8055760b@cloudera.com>
Tested-by: Internal Jenkins

andrwng/kudu,EvilMcJerkface/kudu,andrwng/kudu,EvilMcJerkface/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,cloudera/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,cloudera/kudu,helifu/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,helifu/kudu,andrwng/kudu,EvilMcJerkface/kudu,cloudera/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,InspurUSA/kudu,helifu/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,andrwng/kudu,andrwng/kudu,InspurUSA/kudu,helifu/kudu